adj

• (also figuratively, of fruit) Soft or tender by reason of ripeness; having a tender pulp.
  "a mellow apple"
• (also figuratively, of food or drink, or its flavour) Matured and smooth, and not acidic, harsh, or sharp.
  "The Claret ſmooth, deep as the lip vve preſs, / In ſparkling fancy, vvhile vve drain the bovvl; / The mellovv-taſted Burgundy; and quick, / As is the vvit it gives, the bright Champaign."
• (of soil) Soft and easily penetrated or worked; not hard or rigid; loamy.
  "[A] wyse and counnynge gardener […] will first serche throughout his gardeyne where he can finde the most melowe and fertile erth: and therin wil he put the sede of the herbe to growe and be norisshed: […]"
• (chiefly poetic)
  "Nor autumn yet had bruſh'd from ev'ry ſpray, / With her chill hand, the mellow leaves away; […]"

noun

• (specifically) A comfortable or relaxed mood.
  "Yet, conversely, some people searched for the mellow […] Hope for flower power had faded, though the journey into the mellow did not represent idealism; rather, it spelled escape— […]"
• (African-American Vernacular) Also main mellow: a close friend or lover.
  "I've got attractions like I'm Elvis Costello / Adam Yauch grab the mic 'cause you know you're my mellow"

verb

• (transitive)
  "Then Olives, ground in Mills, their fatneſs boaſt, / And Winter Fruits are mellow'd by the Froſt."
• (transitive)
• (transitive)
  "This City is built of white Sun-burnt brickes, is watered with a ſmall ſtreame, which runs in two parts through the Towne, and meloes moſt of the Gardens and Groues within her, whereby ſhee yeelds a thankfull tribute of ſundry fruits."
• (transitive)
  "VVas thought-exceeding glorification, ſuch a cloyance and cumber vnto me, that I muſt leaue it: as Archeſilaus ouer-melodied, and too-much melovved & ſugred with ſvveet tunes, turned them aſide, and cauſed his ears to be nevv reliſhed vvith harſh ſovver and vnſauory ſounds?"